@article {108,
	title = {Limited hybridization between Quercus lobata and Quercus douglasii (Fagaceae) in a mixed stand in central coastal California},
	journal = {American Journal of Botany},
	volume = {89},
	year = {2002},
	month = {2002},
	pages = {1792-1798},
	abstract = {Many oak species are interfertile, and morphological and genetic evidence for hybridization is widespread. Here we use DNA microsatellite markers to characterize hybridization between two closely related oak species in a mixed stand in central coastal California, Quercus lobata (valley oak) and Q. douglasii (blue oak) (Fagaceae). Genotypes from four microsatellite loci indicate that many alleles are shared between the two species. However, each species harbors unique alleles, and allele frequencies differ significantly. A Bayesian analysis of genetic structure in the stand identified two highly differentiated genetic clusters, essentially corresponding to species assignment based on morphology. Data from the four loci were sufficient to assign all 135 trees to one of the two species. In addition, five putative hybrid individuals having intermediate morphologies could be assigned genetically to one or the other species, and all but one had low probability of hybrid ancestry. Overally, only six (4.6\%) trees showed >0.05 probability of hybrid ancestry, in all cases their probabilities for nonhybrid ancestry were substantially higher. We conclude that adult hybrids of Q. douglasii x Q. lobata are rare at this site and plasticity in morphological characters may lead to overestimates of hybridization among Quercus species.},
	url = {http://www.amjbot.org/cgi/content/abstract/89/11/1792},
	author = {Craft, K.J. and Ashley, M.V. and Koenig, W.D.}
}
@article {129,
	title = {Population differentiation among three species of white oak in northeastern Illinois},
	journal = {Canadian Journal of Forest Research},
	volume = {26},
	year = {2006},
	month = {2006},
	pages = {206-215},
	abstract = {We used microsatellite DNA analysis to examine population differentiation among three species of whiteoak, Quercus alba L., Quercus bicolor Willd., and Quercus macrocarpa Michx., occurring in both pure and mixed stands in northeastern Illinois. Using individual-based Bayesian clustering or principal components analyses, no strong genetic groupings of individuals were detected. This suggests that the three species do not represent distinct and differentiated genetic entities. Nevertheless, traditional approaches where individuals are pre-assigned to species and populations, including F statistics, allele frequency analysis, and Nei},
	author = {Craft, K.J. and Ashley, M.V.}
}
